gpu: nvgpu: add pm_rumtime fixes

Runtime PM is enabled only for iGPU and not for dGPU. For dGPU,
the .probe() of driver pm_runtime_disable()s, if rail-gating is
not enabled. With nvgpu kernel module load/unload, .probe() is
called multiple times for same struct device *. This results
in an overflow of disable_depth (3 bit refcount) and enables
runtime PM on 8th iteration and calls RTPM routines even if it's
disabled.

To effectively manage pm_runtime_disable(), move it from common
nvgpu_remove() to iGPU/dGPU specific routines.

Also, add restore pm_runtime state of device on driver .remove().

Bug 1987855

Change-Id: I781278da546ef9c9ef7d7da7dbea0757df32716f
Signed-off-by: Nitin Kumbhar <nkumbhar@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1770804
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/module.c b/drivers/gpu/nvgpu/os/linux/module.c
index a59ac1f1..e3667947 100644
--- a/drivers/gpu/nvgpu/os/linux/module.c
+++ b/drivers/gpu/nvgpu/os/linux/module.c
@@ -1060,6 +1060,13 @@ static int gk20a_pm_init(struct device *dev)
         return err;
 }
 
+static int gk20a_pm_deinit(struct device *dev)
+{
+        pm_runtime_dont_use_autosuspend(dev);
+        pm_runtime_disable(dev);
+        return 0;
+}
+
 /*
  * Start the process for unloading the driver. Set NVGPU_DRIVER_IS_DYING.
  */
@@ -1309,9 +1316,6 @@ int nvgpu_remove(struct device *dev, struct class *class)
                 platform->secure_buffer.destroy(g,
                                 &platform->secure_buffer);
 
-        if (pm_runtime_enabled(dev))
-                pm_runtime_disable(dev);
-
         if (platform->remove)
                 platform->remove(dev);
 
@@ -1332,8 +1336,11 @@ static int __exit gk20a_remove(struct platform_device *pdev)
         err = nvgpu_remove(dev, &nvgpu_class);
 
         set_gk20a(pdev, NULL);
+
         gk20a_put(g);
 
+        gk20a_pm_deinit(dev);
+
         return err;
 }